package com.tandbergtv.watchpoint.pmm.util;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class RequiredFileFieldsConfig {
	private static final String PRODUCT_DIR = "com.tandbergtv.cms.product.dir";
	private static final String PMM_CONFIG_DIR = "pmm";
	private static final String CONFIG_FILE = "requiredFileFields.txt";

	private static RequiredFileFieldsConfig _instance;

	private List<String> requiredFields = new ArrayList<String>();

	public static synchronized RequiredFileFieldsConfig getInstance()
			throws IOException {
		if (_instance == null) {
			File productConfDir = new File(System.getProperty(PRODUCT_DIR),
					"conf");
			File pmmConfDir = new File(productConfDir, PMM_CONFIG_DIR);
			File confFile = new File(pmmConfDir, CONFIG_FILE);
			_instance = new RequiredFileFieldsConfig(confFile);
		}
		return _instance;
	}

	private RequiredFileFieldsConfig(File file) throws IOException {
		loadFile(file);
	}

	private void loadFile(File file) throws IOException {
		BufferedReader br = null;
		try {
			br = new BufferedReader(new FileReader(file));
			String line = null;
			while ((line = br.readLine()) != null) {
				line = line.trim();
				if (line.equals("") || line.startsWith("#"))
					continue;
				requiredFields.add(line);

			}
		} finally {
			if (br != null)
				br.close();
		}

	}

	public List<String> getRequiredFields() {
		return requiredFields;
	}

}